For the character design, I think it's quite close to the manga (except Yayoi). Note that Kobayashi Jin changed his art style around the end of vol.2 to the beginning of vol.3 then changed again in the middle of vol.4, so the anime character design is close to his current art style rather than first few chapters.

Comparison image (from vol.3, since I don't have a scanner for vol.4):